package com.atcumt.alibaba;

import java.util.Scanner;

/* 
 * 5
 * ca
 */
public class Ali01 {
    
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] nums = new int[24];
        nums[0] = 1;
        String[] chars = {"a","b","c","d","e","d","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        for (int i = 1; i < 24; i++) {
            nums[i] = nums[i - 1] * 2;
        }
        StringBuilder sb = new StringBuilder();
        int index = 23;
        while (index >= 0) {
            while (n >= nums[index]) {
                sb.append(chars[index]);
                n -= nums[index];
            }
            index--;
        }
        System.out.println(sb.toString());
    }
}
